ADD: added a valid value

include/SimCore/Position.hpp

@@ -7,6 +7,7 @@
 #include <GeographicLib/Geodesic.hpp>
 #include <GeographicLib/GeodesicLine.hpp>
 #include <GeographicLib/Constants.hpp>
+#include <atomic>
 #include <memory>
 #include <mutex>
 
@@ -24,6 +25,7 @@ namespace SimCore {
             */
             Eigen::Vector3d getGeocentricPos();
             void getGeocentricPos(double &lat, double &lon,double &h);
+
             /**
             * @brief returns a eigen vector3d with the lat, lon, height coordinates
             * @return Eigen::Vector3d
@@ -33,6 +35,7 @@ namespace SimCore {
             void setGeocentricPos(double X, double Y, double Z);
             void setGeodesicPos(double lat, double lon, int height);
 
+            bool isValid();
 
             double distanceToPosition(Position &p2);
 
@@ -53,8 +56,7 @@ namespace SimCore {
 
             mutable std::mutex mx;
 
-
-
+            std::atomic_bool valid_;
 
     };